A photographic optical device which is mounted on a portable apparatus is provided with a movable body including a lens, a lens drive mechanism for magnetically driving the movable body in an optical axis direction, and a photographing unit in which an imaging element is supported on a support body. In the photographic optical device, various types of a shake correction mechanism are mounted for restraining disturbances of a photographed image due to a handshake of a user. As such a shake correction mechanism, a structure where a shake correction lens provided in a photographing unit is shifted in a direction canceling the shake, a structure where an imaging element is shifted in a plane perpendicular to the optical axis, and the like have been practically used.
A structure where a shake correction mechanism is incorporated into a photographing unit is capable of being adopted in a photographic optical device which is mounted on a relatively large portable apparatus such as a digital camera. However, in a photographic optical device which is mounted on a small portable apparatus such as a cell phone with camera, a photographing unit is smaller and thus the shake correction mechanism is unable to be incorporated into the photographing unit.
In order to prevent this problem, in a photographic optical device, it has been proposed that a shake correction mechanism is structured between a photographing unit and a fixed body which supports the photographing unit. In a case that this structure is adopted, the photographing unit is structured as a movable module which is capable of displacing in a direction intersecting the optical axis on the fixed body (see Patent Literature 1).
The shake correction mechanism described in Patent Literature 1 is structured so that a photographing unit is elastically urged by a flat spring against a pivot part formed on a fixed body and the photographing unit is capable of rocking with the pivot part as a supporting point. The photographing unit is rocked around an X-axis perpendicular to an optical axis by a first photographing unit drive mechanism which is arranged at one side portion displaced from the pivot part, and the photographing unit is rocked around a Y-axis perpendicular to the optical axis by a second photographing unit drive mechanism which is arranged at another one side portion displaced from the pivot part.
Further, in another photographic optical device, another system has been proposed for correcting a hand shake occurred at the time of photographing. In other words, as shown in FIG. 20, an object side end part of a movable module 1081 in which a lens 1083 and an imaging element 1085 are supported on a support body 1082 is supported by a fixed body 1089 through an elastic member 1088 and actuators 1087 are disposed on side faces of the movable module 1081. The actuators 1087 rock an end part on an opposite side to an object to be photographed side of the movable module 1081 (end part on the imaging element side) as shown by the arrow “P” on the basis of a detection result of a shake detection sensor 1086 to correct the hand shake (see Patent Literature 2).
[PTL 1] Japanese Patent Laid-Open No. 2007-310084
[PTL 2] Japanese Patent Laid-Open No. 2007-129295
However, like the shake correction mechanism described in Patent Literature 1, in a first photographing unit drive mechanism or in a second photographing unit drive mechanism which is arranged at one side portion with respect to the pivot part, even when a positional relationship between the drive mechanism and the pivot part is slightly displaced, a driving power is varied and thus it is difficult to obtain a stable thrust force.
Further, the flat spring which is used in the shake correction mechanism described in Patent Literature 1 is formed in a shape whose spring constants in an X-axis direction and a Y-axis direction are largely different from each other. Therefore, when both of the first photographing unit drive mechanism and the second photographing unit drive mechanism are driven, a magnitude and a direction of an urging force which is applied to the photographing unit by the flat spring are not provided with linearity. Therefore, control for the first photographing unit drive mechanism and the second photographing unit drive mechanism are extremely complicated.
In addition, like the shake correction mechanism described in Patent Literature 1, in a structure that a photographing unit drive magnet is provided on a fixed body side and a photographing unit drive coil is provided on a photographing unit side which is a movable body side, since wiring lines for power supply are required to connect with the photographing unit drive coil, the number of wiring lines to the photographing unit is increased and thus a wiring structure is complicated and, on the photographing unit side, it is difficult to increase a winding number of the photographing unit drive coil. Further, since the photographing unit drive coil whose mass is larger than that of the photographing unit drive magnet is provided on the photographing unit side which is the movable body side, a large force is required to rock the photographing unit and its control is difficult.
Further, like the shake correction mechanism described in Patent Literature 2, in a system in which an end part on an imaging element side of a movable module is rocked, the movable module is unable to be appropriately rocked. In other words, a flexible wiring member such as a flexible circuit board or resin coated lead wires which is electrically connected with an imaging element and a shake detection sensor is drawn out from the end part on the imaging element side of the movable module. Therefore, the flexible wiring member is also required to be elastically deformed for rocking the end part on the imaging element side of the movable module and thus it is difficult to speedily rock the movable module. Further, when the end part on the imaging element side of the movable module is rocked, the flexible wiring member is also elastically deformed. Therefore, an unnecessary force is applied to the end part of the imaging element side of the movable module due to a shape returning force of the flexible wiring member and a magnitude of the shape returning force is varied depending on a deformed state of the flexible wiring member and thus it is difficult that the end part on the imaging element side of the movable module is rocked appropriately. Especially, when a magnetic drive mechanism is used as an actuator for shake correction, in comparison with a case that a piezo-electric element is used like the structure described in Patent Literature 2, the movable module is driven in an elastic and non-contact manner and thus the shake correction is easily affected by the flexible wiring member.
In view of the problems described above, at least an embodiment of the present invention provides an optical unit with shake correcting function which is capable of surely correcting a shake to a movable module by stabilizing a force applied to the movable module.
Further, at least an embodiment of the present invention provides a photographic optical device which is hard to be affected by deformation of a flexible wiring member that is drawn out from a movable module when the movable module on which a lens and an imaging element are mounted is rocked for correcting a shake or, when the movable module on which a shake detection sensor for a hand shake or the like is mounted in addition to the lens and the imaging element is rocked for correcting a shake.